People nowadays are increasingly paying attention to the concept of health care. Body fitness has become a new manner of exercising. Along with the development and progress of modern science and technology, exercise equipments for assisting users in performing training of their body parts have emerged, such as treadmills, steppers, sit-up boards, etc. However, most of the exercise equipments can only be used for a single kind of training program, and cannot permit the user to use the same equipment for training various body parts. In addition, since most of the exercise equipments have bulky volumes, if the consumers buy and place them in their homes, the exercise equipments will take up a lot of interior space when not in use. This causes the people to reduce their desire to buy the exercise equipment, and choose to do the body training at the gym or fitness center, instead of doing the fitness training at their own homes.
Further, in an exercise using a sit-up board of one of the aforementioned exercise equipment, the user mainly rely on the strength of the waist to raise his upper body. However, the user often ends up with waist muscle strain because the backward leaning angle is too large and the applied force is excessive.